3D Orbital Architecture of Exoplanetary Systems: KAM-Stability Analysis

We study the KAM-stability of several single star two-planetnonresonant extrasolar systems. It is likely that the observedexoplanets are the most massive of the system considered. Therefore,their robust stability is a crucial and necessary condition for thelong-term survival of the system when considering potentialadditional exoplanets yet to be seen. Our study is based on theconstruction of a combination of lower-dimensional elliptic and KAMtori, so as to better approximate the dynamics in the framework ofaccurate secular models. For each extrasolar system, we explore theparameter space of both inclinations: the one with respect to theline of sight and the mutual inclination between the planets. Ourapproach shows that remarkable inclinations, resulting inthree-dimensional architectures that are far from being coplanar,can be compatible with the KAM stability of the system. We findthat the highest values of the mutual inclinations are comparable tothose of the few systems for which the said inclinations are determinedby the observations.